The present invention relates to a device for supplying polyphase image signals to a liquid crystal displaying apparatus.
Image signals to be displayed are converted into polyphase signals of N-phases (N being a natural number of 2 or more) and supplied to a liquid crystal displaying apparatus. An image signal of each phase has an occupied bandwidth corresponding to 1/N of that of the original image signals.
The polyphase signals are supplied to an active-matrix liquid crystal displaying apparatus with switching transistors, such as, thin film transistors (TFT) and MOS transistors, provided on intersections of signal electrodes (lines) and scanning electrodes.
The switching transistors switch a voltage supplied to each pixel to separate two-dimensionally arranged pixels for non-crosstalk driving if memory devices for holding voltages corresponding to image signal per pixel reveal low frequency characteristics or the switching transistors reveal low switching response.
When projecting an image onto a screen by a projection-type displaying apparatus, the displaying apparatus may be set on the screen's front or back side. The image is reversed in a horizontal direction of the screen when projected on the back side, for example.
An image projected onto a screen by an active-matrix liquid crystal displaying apparatus supplied with single phase image signals can be reversed by switching a shifting direction of a horizontal shift register of a horizontal driver of the displaying apparatus.
On the other hand, if the active-matrix liquid crystal displaying apparatus is supplied with polyphase image signals, such shifting direction switching reverses an order of arrangement of pixels group, the number of pixels in each group corresponding to the number of phases of the image signals, however, not an order of arrangement of pixels in each group. A normal image thus cannot be displayed on the screen.
A device for supplying polyphase image signals to the active-matrix liquid crystal displaying apparatus thus requires reversing the order of arrangement of pixels in each group for applicability in image projection on the screen from both the front and back sides.
However, such a device is fabricated into a one chip IC with a lot of data input/output terminals and signal switching circuitry, that is, a costly large scale one chip IC.
On the other hand, such a device with a plurality of ICs requires data communications among the ICs for image switching in a horizontal direction of a screen. Many costly data input/output terminals are thus required per IC.